1:查看工资高于2000的员工
select ename,sal from emp_xiangyoulu where sal>2000;
select ename,deptno,sal from emp_xiangyoulu where sal>2000 order by sal desc;
2:查看职位不是"CLERK"的员工
select ename,job from emp_xiangyoulu where job <>'CLERK';
select ename,job from emp_xiangyoulu where job != 'CLERK';
3:查看工资在1000-2500之间的员工
select ename,sal from emp_xiangyoulu where sal between 1000 and 2500;
select ename,deptno,sal from emp_xiangyoulu where sal between 1000 and 2500 order by sal;
4:查看名字是以K结尾的员工
select * from emp_xiangyoulu where ename like '%K';
select ename,deptno,sal from emp_xiangyoulu where ename like '%K';
5:查看20,30号部门的员工
select * from emp_xiangyoulu where deptno=20 or deptno=30;
select * from emp_xiangyoulu where deptno in(20,30);
6:查看奖金为NULL的员工
select ename,comm from emp_xiangyoulu where comm is null;
select * from emp_xiangyoulu where comm is null order by deptno;
7:查看年薪高于20000的员工
select ename,sal*12 from emp_xiangyoulu where sal*12>20000;
select ename,sal*12 totalSal from emp_xiangyoulu where sal*12>20000;
8:查看公司共有多少种职位
select count(distinct job) from emp_xiangyoulu ;
--select count(job) from (select ceil(avg(sal)),job from emp_xiangyoulu group by job);
9:按部门号从小到大排列查看员工
select * from emp_xiangyoulu order by deptno asc;--顺序(默认)
select * from emp_xiangyoulu order by deptno desc;--倒叙
10:查看每个部门的最高，最低，平均工资，和工资总和
select max(sal),min(sal),ceil(avg(sal)),sum(sal),deptno from emp_xiangyoulu
group by deptno order by deptno;
11:查看平均工资高于2000的部门的最低薪水
--select avg(sal),deptno from emp_xiangyoulu group by deptno where avg(sal)>2000; --报错!
select avg(sal),deptno from emp_xiangyoulu group by deptno having avg(sal)>2000;
select avg(sal),deptno from emp_xiangyoulu group by deptno having deptno in(
select deptno from emp_xiangyoulu group by deptno having avg(sal)>2000);
12:查看在NEW YORK工作的员工
select * from emp_xiangyoulu e join dept_xiangyoulu d
on e.deptno=d.deptno and d.loc='NEW YORK';
select * from emp_xiangyoulu e,dept_xiangyoulu d where e.deptno=d.deptno and d.loc='NEW YORK';
13:查看所有员工及所在部门信息，若该员工没有部门，则部门信息以NULL显示
select * from emp_xiangyoulu e left outer join dept_xiangyoulu d on e.deptno=d.deptno;
14:查看ALLEN的上司是谁
select e.ename,e.mgr,m.empno,m.ename from emp_xiangyoulu e join emp_xiangyoulu m
on e.mgr=m.empno and e.ename='ALLEN';
15:查看SMITH的上司在哪个城市工作?
select m.ename,d.loc from emp_xiangyoulu e join emp_xiangyoulu m on e.mgr=m.empno
join dept_xiangyoulu d on e.deptno=d.deptno
where e.ename='SMITH';
16:查看平均工资高于2000的那些部门名字以及所在城市?
select distinct e.deptno,d.dname,d.loc from emp_xiangyoulu e join dept_xiangyoulu d on e.deptno=d.deptno
and e.deptno in(select deptno from emp_xiangyoulu group by deptno having avg(sal)>2000);
SELECT e.deptno,AVG(e.sal),d.dname,d.loc FROM emp_xiangyoulu e ,dept_xiangyoulu d
WHERE e.deptno=d.deptno
GROUP BY e.deptno,d.dname,d.loc HAVING AVG(e.sal)>2000;
17:在NEW YORK工作的员工有多少人?
select count(1) from emp_xiangyoulu e join dept_xiangyoulu d
on e.deptno=d.deptno and d.loc='NEW YORK';
18:在DALLAS工作的员工的平均工资是多少?
select avg(e.sal) from emp_xiangyoulu e join dept_xiangyoulu d
on e.deptno=d.deptno where d.loc='DALLAS';